A group of researchers in the School of Optometry are seeking support for the purchase of a biopter which will precisely quantify physical dimensions of the eye, optical characteristics, eye position and accommodation. The instrument is produced by S.R.I. International and consists of an A-B scan, binocular eye-tracker, automatic optometer, fundus inspection unit and 3-D visual stimulus deflector. The three categories of projects proposed to utilize this equipment are: 1) visual sensitivity studied with stabilized retinal images, 2) optics and dimensions of the eye, and 3) sensory (afferent) input for oculomotor control as revealed by open loop studies of eye movements and their interactions with accommodation. Proposed experiments will provide a greater understanding and ability to diagnose and treat visual sensory disorders including amblyopia, diabetes, local retinal pathology, visual deprivation in aphakic neonates and drug induced effects upon the visual system. The equipment will also be used to examine the genesis of refractive error as well as visual motor disorders including latent nystagmus and strabismus. The high precision equipment that is requested will provide researchers on the Berkeley campus in psychophysics, ocular motility, anatomy and vegetative physiology, the ability to examine complex sensory-motor disorders under highly controlled conditions such that the individual effects of sensory and motor disturbances upon visual performance can be determined.